:root {
  --bg: #f6f3ee;
  --panel: rgba(255, 252, 247, 0.82);
  --ink: #1f1c18;
  --muted: #7b736b;
  --line: #d8d1c7;
  --line-strong: #b8afa3;
  --block: #fffdf9;
  --block-selected: #ede6db;
  --block-derived: #f4efe8;
  --success: #2f4f3a;
  --invalid: #7b5047;
  --shadow: 0 24px 60px rgba(31, 28, 24, 0.05);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.9), transparent 42%),
    linear-gradient(180deg, #fbf9f4 0%, var(--bg) 100%);
  color: var(--ink);
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
}

button {
  font: inherit;
}

.room {
  display: grid;
  place-items: center;
  padding: 5.5rem 2rem 0;
}

.instruction {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
  letter-spacing: 0.05em;
  text-align: center;
}

.puzzle {
  width: min(760px, 100%);
  display: grid;
  gap: 2rem;
  padding: 2rem;
  border: 1px solid rgba(184, 175, 163, 0.55);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.level-bar,
.controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.eyebrow,
.level-count,
.level-note,
.rule-label,
.step-explanation,
.hint-text {
  margin: 0;
  color: var(--muted);
  letter-spacing: 0.05em;
}

.eyebrow {
  font-size: 0.78rem;
  text-transform: uppercase;
}

.level-title {
  margin: 0.35rem 0 0;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 400;
}

.level-count,
.level-note,
.rule-label,
.step-explanation,
.hint-text {
  font-size: 0.95rem;
}

.workspace {
  display: grid;
  gap: 2.5rem;
  justify-items: center;
  padding: 2rem 0 1rem;
  border-top: 1px solid rgba(216, 209, 199, 0.7);
  border-bottom: 1px solid rgba(216, 209, 199, 0.7);
}

.blocks {
  display: flex;
  gap: 0.9rem;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  min-height: 5rem;
}

.symbol-block {
  min-width: 116px;
  padding: 0.95rem 1.3rem;
  border: 1px solid var(--line);
  background: var(--block);
  color: var(--ink);
  font-size: 1.3rem;
  cursor: pointer;
  transition:
    transform 180ms ease,
    background 180ms ease,
    border-color 180ms ease,
    opacity 180ms ease,
    box-shadow 180ms ease;
}

.symbol-block:hover:not(:disabled) {
  transform: translateY(-1px);
  border-color: var(--line-strong);
}

.symbol-block.selected {
  background: var(--block-selected);
  border-color: var(--ink);
  box-shadow: inset 0 0 0 1px rgba(31, 28, 24, 0.08);
}

.symbol-block.derived {
  background: var(--block-derived);
}

.symbol-block.newly-created {
  animation: emerge 380ms ease;
}

.symbol-block:disabled {
  cursor: default;
  opacity: 0.66;
}

.blocks.invalid {
  animation: shake 220ms ease;
}

.target {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  font-size: clamp(1.8rem, 5vw, 2.4rem);
}

.unknown {
  min-width: 3rem;
  min-height: 3rem;
  display: grid;
  place-items: center;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  transition: color 180ms ease, border-color 180ms ease;
}

.unknown.solved {
  color: var(--success);
  border-color: var(--success);
}

.turnstile {
  color: var(--muted);
}

.feedback {
  min-height: 5.75rem;
  display: grid;
  gap: 0.35rem;
  justify-items: center;
}

.result {
  margin: 0;
  min-height: 1.5rem;
  color: var(--muted);
  font-size: 1rem;
  letter-spacing: 0.04em;
}

.result.success {
  color: var(--ink);
}

.result.invalid {
  color: var(--invalid);
}

.rule-label {
  min-height: 1.2rem;
}

.step-explanation,
.hint-text {
  min-height: 1.2rem;
  max-width: 34rem;
  text-align: center;
  line-height: 1.45;
}

.step-explanation {
  color: rgba(31, 28, 24, 0.8);
}

.hint-text {
  font-style: italic;
}

.controls {
  flex-wrap: wrap;
}

.control-button {
  padding: 0.7rem 1rem;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: background 180ms ease, border-color 180ms ease, color 180ms ease;
}

.control-button:hover:not(:disabled) {
  background: rgba(237, 230, 219, 0.45);
  border-color: var(--line-strong);
}

.control-button.primary {
  border-color: var(--ink);
}

.control-button:disabled {
  cursor: default;
  opacity: 0.4;
}

.site-footer {
  margin-top: 2.5rem;
  padding: 1.5rem 1rem 1.8rem;
  border-top: 1px solid rgba(184, 175, 163, 0.24);
}

.site-footer__inner {
  display: grid;
  justify-items: center;
  gap: 0.35rem;
  text-align: center;
}

.site-footer__symbol {
  display: block;
  width: 18px;
  height: 18px;
  opacity: 0.78;
}

.site-footer__text {
  margin: 0;
  font-size: 0.76rem;
  color: var(--muted);
  letter-spacing: 0.01em;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }

  25% {
    transform: translateX(-5px);
  }

  75% {
    transform: translateX(5px);
  }
}

@keyframes emerge {
  0% {
    opacity: 0;
    transform: translateY(10px);
  }

  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 640px) {
  .room {
    padding: 1rem 1rem 0;
  }

  .instruction {
    position: static;
    transform: none;
    padding-top: 1rem;
  }

  .puzzle {
    padding: 1.5rem;
    margin-top: 1rem;
  }

  .level-bar,
  .controls {
    align-items: flex-start;
    flex-direction: column;
  }

  .symbol-block {
    min-width: 96px;
    font-size: 1.15rem;
  }

 .site-footer {
    margin-top: 2rem;
    padding: 1.35rem 1rem 1.6rem;
  }
}